Steam sterilizable package and method of making the same



NW. 1968 J. c. SELLERS 3,41,95

- STEAM STERILIZABLE PACKAGE AND METHOD OF MAKING THE SAME Filed July 14, 1967 2 Sheets-Sheet l I N VEN TOR.

B Y ATTORNEYS Nam 12, ma J. c. SELLERS STEAM STERILIZABLE PACKAGE AND METHOD OF MAKING THE SAME 2 Sheets-Sheet 2 Filed July 14, 1967 Q INVENTORL ATTORNEYS United States Patent 3,410,395 STEAM STERILIZABLE PACKAGE AND METHOD OF MAKING THE SAME John C. Sellers, Barrington, Ill., assignor to General Binding Corporation, Northbrook, Ill., a corporation of Delaware Filed July 14, 1967, Ser. No. 653,406

8 Claims. (Cl. 206-632) ABSTRACT OF THE DISCLOSURE A steam sterilizable package is made by punching steam passage holes through a generally impervious heat sealable film while carried on a backing sheet and then bonding the film to an imperforate steam-pervious paper sheet. Completion of a container about contents to be protected in sterile condition is effected by marginally peelably seaming the film or the backing sheet to a confronting packaging sheet or panel, steam sterilization then being effected through the paper sheet at the holes.

This invention relates to a new and improved steam sterilizable package and method of making the same, and is more particularly concerned with providing a container within which the contents can be sterilized after being sealed within the container and from which the contents may be removed by peeling the seals apart.

Heretofore sterilized contents have been packaged by enclosing the same Within a sealed container. Where the packaging material has comprised a foil, a thermoplastic sheet or film, or a lamination of such materials which are generally impervious to steam or gas, sterilization of the contents has presented a distinct problem.

In order to attain the advantages of steam or gas sterilization after packaging, a part of the package has been made of a permeable paper. In opening such a package it has heretofore been necessary to tear loose at least some of the paper fibers, creating an undesirable condition where the contents must be released for use in an operating room or other area which should be maintained dust free.

It is, accordingly, an important object of the present invention to overcome the foregoing and other defects and deficiencies of prior structures and practice and to provide a new and improved steam sterilizable package and method of making the same.

Another object of the invention is to provide a steam sterilizable package in which the contents are adapted to be steam sterilized after the package has been scaled, and from which the sterilized contents are adapted to be removed without any release of fibers or dust from the packaging material.

A further object of the invention is to provide a new and improved steam sterilizable package in which the packaging components are heat sealed in a manner to enable them to be peeled apart for access to the sterilized contents.

Still another object of the invention is to provide a new and improved steam sterilizable package and method of making the same utilizing a special laminated material.

Where the term steam is used it will be understood to include gas.

Other objects, features, and advantages of the present invention will'be readily apparent from the following detailed description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a fragmental isometric view of a punched laminated panel at one stage in the making of a package according to the present invention;

FIGURE 2 is a fragmental edge elevational view, partially in section of a further step in making the laminated packaging material;

FIGURE 3 is a sectional view through a completed package according to the invention;

FIGURE 4 is a sectional view through a modified package according to the invention;

FIGURE 5 is a fragmental isometric view of a punched laminated packaging material assembly in its initial form;

FIGURE 6 is an edge elevational view of the laminated assembly of FIGURE 5 with another lamination added thereto;

FIGURE 7 is a sectional view through a container embodying the laminated material of FIGURE 6; and

FIGURE 8 is a sectional view through a modified container utilizing a laminated assembly on the order of that in FIGURE 6.

According to the invention, a steam sterilizable package is made by punching steam passage holes through a generally impervious and preferably heat sealable film layer while carried on a backing sheet. Then the film is bonded as a perforated liner or coating to a protective imperforate steam-pervious paper sheet layer. Thereafter, the backing sheet may be stripped from the film or may be left thereon as a reinforcing and stiffening layer of the final product. Completion of a container about contents to be protected in sterile condition is effected by marginally non-fusedly seaming as by heat sealing the film or the backing sheet to a confronting package sheet or panel. Steam sterilization of the package contents may then be effected through the paper sheet and through the passage holes.

In making the steam sterilizable package, a laminated packaging material is made. By way of example as shown in FIGURES l and 2, a film 1 of heat sealable material is applied to a backing sheet 2. The laminated material is then punched to provide a suitable number of holes 3 therethrough in a desirable size and in any preferred pattern spacing, leaving adequate imperforate marginal areas about the perforated area. Material for the film 1 suitable for steam sterilizable packaging comprises a thermoplastic resin of which polyethylene is: preferred but may also be polypropylene, ethylene/ethylacrylate, ethylene/ vinyl acetate, and ethylene/acrylic acid copolymer, polyvinyl chloride, and the like. While the backing sheet 2 is desirably foil such as aluminum foil, cellophane, Mylar, polyster, nylon, polypropylene and like films may be used for the purpose.

After the holes 3 have been punched, the backed up heat scalable film 1 is laminated with and bonded to a suitably porous but eificiently protective imperforate paper sheet 4 as by heat lamination. Thereafter, if desired, though not necessarily, the backing sheet or film 2 may be stripped from the heat scalable film 1. Such stripping is especially in order where the material of the backing sheet 2 will not coact with the material desired for completition of the package in a peelable seam relationship.

Inasmuch as thelaminated punched film coated paper sheet or panel may be constructed in any of a desirable range of weights or thicknesses, pliability, stiffness, sizes and the like to meet practical requirements, a wide range of versatility for packaging contents that are desirably steam sterlized after packaging, such as surgical supplies and equipment, may be conveniently accommodated in Wrappings or containers suitable for the particular contents. For example, in FIGURE 3, a pouch type package 5 is depicted in which contents, schematically represented by the dot-dash outline C, are enclosed to be steam sterilized and then maintained in sterile condition within the package until removed therefrom for use. While the pouch package 5 may comprise a sheet of the laminated punched film coated paper folded upon itself, as indicated in dash outline to envelope the contents C, so that the single folded sheet provides, in effect, confronting packaging sheets or panels, the laminated panel may be assembled with another separately formed sheet or panel. In either form, the confronting panels have their margins in face-to-face abutment and joined by a peelable seam 7. In an especially desirable manner of seaming, a non-fused heat sealed connection is provided. The width and resistance to separation of the seam 7 is such as to withstand the usual handling stresses without parting. Further, the character of the seaming is such as to withstand and avoid separation under steam sterilization. Where heat sealing is employed the effective sealing temperature is selected to be substantially greater than the maximum temperature anticipated to be encountered during steam sterilization. On the other hand, the character of the seam 7 is such as to enable ready deliberate peeling separation upon application of moderate opposite pulling force on the joined margins of the packaging material. In the package it will be observed that the scams 7 comprise, on both of the confronting package panels the marginally joined portions of the liners 1, both of which are desirably provided with the steam passage perforations 3 for highly efficient sterilization. After the package has been completed, it may be placed in an autoclave in which steam sterilization is effected, the steam readily entering thhe interior of the package through the outer paper lamina 4 and through the perforation passages 3 to the interior of the package. After sterilization the relatively impervious major areas of the liners 1 afford excellent protection against contamination. While the liners 1 may be such film thinness as to be relatively fragile, the paper sheet 4 affords adequate strength and resistance to rupture.

Another type of package 8 is depicted in FIGURE 4 comprising a tray 9 having lateral flange structure about its top to which a laminated punched film coated or lined paper sheet panel is marginally peelably seamed as at 11 to the flange 10. The tray 9 may be made from any suitable plastic or non-plastic material and with the flange structure 10 either of itself or when coated with a film of suitable material adapted for peelable seaming coaction with the perforated liner film 1, as by heat sealing. After the laminated panel has been attached as a lid to the tray 9, the contents C within the package 8 are adapted to be sterlized by steam sterilization, the passage perforations 3 enabling the sterilizing steam to enter the closed container through those portions of the paper sheet 4 which extend protectively across the perforations.

In the modification of FIGURES 5 and 6, a liner film 1' is shown which is of sufficient gage or thickness to be substantially self-sustaining and is laminated to a backing sheet 2' in only that area provided with the punched passage holes 3', leaving substantial marginal areas of the film 1' free. The backing sheet 2 facilitates the punching operation, and, in this instance, is permitted to remain on the liner film 1' as a stiffening member or reinforcement. A protective imperforate steam-pervious paper sheet 4' is laminated in coextensive relation to the film 1' and covers over the holes 3'. In producing a pouch-type package 5' as shown in FIG. 7, the marginal portions of the film 1' exposed beyond the perimeter of the backing sheet 2 are peelably seamed at 7' with a confronting packaging sheet or panel which may be a complementary counterpart as shown.

In providing a tray-like package 8 as shown in FIG. 8 the backing sheet 2 may be coextensive with the liner film 1, which in this instance may be of such thinness as merely to provide a coating permitting eflicient heat bonding lamination of the paper sheet 4' to the punched film and the backing sheet 2. In other words, in this instance the film 1' serves as a laminating medium. Where the tray 9 is compatible with the material of the backing sheet 2 to afford peelable seams with the flanges 10' of the tray member, direct face-to-face peelable seaming may 4 be effected of the laminated sheet as a lid for the tray. Where the material of the tray 9' is not of a character to permit peelable seaming, as by heat sealing, a coating 12 of a material which will peelably seam with the sheet 2' may be employed. For example, where the backing sheet 2' is foil and the tray 9 is of a paper material, the seaming layer 12 may comprise a coating on the flange 10 of a material having the characteristics of polyethylene or which will readily provide a heat seal seam with the foil and which may be readily peeled apart when the contents C are to be removed from the package, but which will retain the thoroughly sealed protective package closed until that time.

From the foregoing it will be apparent that while in every instance a protective package is provided which enables eflicient steam sterilization of the contents, the contents are completely protected against contamination. When it is desired to remove the contents from the package, that is readily effected without any need to rupture the packaging material, but simply by peeling open the seam joining the package material panels. Such peeling is accomplished without tearing or loosening of any fibers or particles of the materials because the seam peels cleanly and is free from any fibrous material which might be torn loose and dislodged in opening the package.

It will be understood that variations and modifications may be effected without departing from the spirit and scope of the novel concepts of this invention.

I claim as my invention:

1. A steam sterilizable package comprising:

confronting packaging panels enclosing package contents;

at least one of said panels comprising sterilizing steam permeable layer and coextensive substantially impermeable layer laminated thereto and having holes therethrough alfording sterilizing steam passage;

and a peelable seam joining said impermeable layer of said one panel to the remaining of said panels, maintaining the package closed to protect said contents against contamination and enabling dust-free opening.

2. A package as defined in claim 1, in which said peelable seam is a non-fused heat sealed seam.

3. A steam sterilizable package comprising:

confronting packaging panels enclosing package contents;

at least one of said panels comprising sterilizing steam imperforate permeable layer and a coextensive substantially impermeable layer laminated thereto and having holes therethrough affording sterilizing steam passage;

a backing sheet joined to said imperforate permeable layer by said impermeable layer and having holes therethrough aligned with the holes in the impermeable layer;

and a seam joining said one panel to the remaining of said panels and maintaining the package closed to protect said contents against contamination.

4. A method of making a steam sterilizable package comprismg:

laminating a substantially impervious layer having perforations through a predetermined area thereof to an imperforate pervious layer to provide a packaging material laminated panel;

and adjoining said panel to a confronting packaging material panel along a cleanly peelable seam which enables dust-free opening.

5. The method according to claim 4, in which said panels having abutting surfaces at said seam which are non-fusibly heat sealable, and non-fusibly heat sealing said surfaces together.

6. The method according to claim 4, in which said impervious 'layer comprises a themoplastic film, joining said thermoplastic film in face-to-face relation to a backing sheet, and punching said perforations through the film 5 and backing sheet before laminating the film to the pervious imperforate layer.

7. The method according to claim 6, which includes stripping the backing sheet from said film after the film has been laminated to the pervious imperforate layer.

8. The method according to claim 6, wherein said backing sheet remains in laminated assembly with the film and the pervious imperforate sheet, applying a film of a heat scalable material to the confronting packaging material panel surfaces along said seam, and non-fusedly heat sealing the seam.

References Cited UNITED STATES PATENTS 2,997,224 8/1961 Stannard 22953 3,286,832 11/1966 Pilger 206-632,

DAVID M. BOCKENEK, Primary Examiner. 

